Flat panel display and backlight module thereof

ABSTRACT

A flat panel display and backlight module thereof. The backlight module comprises a frame, a flexible printed circuit board, and at least one electrical connection port. The flexible printed circuit board is encircled by the frame. The electrical connection port is disposed on the flexible printed circuit board, connecting the flexible printed circuit board and an external printed circuit board.

BACKGROUND

The invention relates to a flat panel display, and in particular to a flat panel display and a backlight module thereof.

Flexible printed circuit board (FPCB) is widely used in electronic devices for electrical connection requiring elasticity and light weight, enabling internal space of electronics to be effectively utilized and convenient to assemble.

FIG. 1 is a schematic view of a conventional backlight 10 for a flat panel display. The conventional backlight 10 comprises a frame 11, a flexible printed circuit board 12, a light source (not shown), and other elements. The flexible printed circuit board 12 is generally long and thin, and disposed on a front side F′ of the backlight module 10. A portion of the flexible printed circuit board 12 protrudes from the frame 11, connecting to other circuit boards in the flat panel display, providing signal transfer and power to a light source. Additionally, signals transmitted by or received from the backlight module 10 are transmitted via the flexible printed circuit board 12 to other interfaces of the flat panel display. Two conventional connection methods frequently used to connect the flexible printed circuit board and other circuit boards of the flat panel display are shown in FIGS. 2A and 2B, respectively.

FIG. 2A is a side view of an assembly of a printed circuit board 15 and a backlight module 10 of a conventional flat panel display 100. FIG. 2B is a side view of another assembly of a printed circuit board 15 and a backlight module 10 of the conventional flat panel display 100.

As shown in FIG. 2A, the flat panel display 100 comprises a printed circuit board 15 and a backlight module 10 disposed thereon. A flexible printed circuit board 12 for light source protrudes from the frame of the backlight module 10 and connects to the printed circuit board 15 via a connector 16.

The disadvantage of the design is that connector 16, having large volume, requires additional space, and thus, the connector 16 occupies most usable space on the circuit board 15 or the flexible circuit board 12. The connector must be assembled manually, whereby labor time and costs cannot be effectively controlled.

FIG. 2B is a schematic view of a flexible printed circuit board 12 for light source, welded to bare copper (not shown) of another printed circuit board 15 of a flat panel display by solder 17. In this method, since connectors are eliminated, material costs are reduced, but assembly time and costs cannot. Welding quality depends on skill and performance and can vary with the parameters of pressure welding, machines, and thickness of solder. Thus, connection quality is difficult to control. If the product must be repaired or reassembled, the flexible printed circuit board can possibly overheat, deform, or even break such that the product is irreparable. If assembly fails, materials are wasted, increasing assembly time, and assembly costs cannot be effectively controlled.

Note that, since the flexible printed circuit board protrudes from the frame to connect to an external circuit, strength of the frame is not strong enough, and when the frame is compromised, display quality of the flat panel is affected accordingly.

SUMMARY

Embodiments of the invention provide a flat panel display and a backlight module thereof to eliminate the shortcomings described such that the space in the circuit board is conserved, providing easy reassembly, low costs, and high quality control.

Further provided is a backlight module comprising a frame, a circuit board, and at least one electrical connection port. The circuit board is encircled by the frame. The electrical connection port is disposed on the circuit board, connecting to an external circuit board.

The frame comprises at least one opening, corresponding to the electrical connection port, passing through the opening and exposed to the outside of the frame.

The electrical connection port comprises elastic conductor, metal elastic plate, or bare copper.

The electrical connection port is curved.

The circuit board comprises a flexible printed circuit board (FPCB) or printed circuit board (PCB).

Further provided is a flat panel display comprising a first circuit board, a first electrical connection port, a backlight module, and a panel. The first electrical connection port is disposed on a surface of the first circuit board. The backlight module, connected to the first circuit board, comprises a frame, a second circuit board, and a second electrical connection port. The second circuit board is encircled by the frame. The second electrical connection port is disposed on a surface of the second circuit board. The first electrical connection port contacts the second electrical connection port, connecting the second circuit board and the first circuit board. The panel is connected to the second circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:

FIG. 1 is a schematic view of a conventional backlight module;

FIG. 2A is a side view of an assembly of a printed circuit board and a backlight module of a conventional flat panel display;

FIG. 2B is a side view of another assembly of a printed circuit board and a backlight module of the conventional flat panel display;

FIG. 3A is a schematic front view of a backlight module of an embodiment of the invention;

FIG. 3B is a schematic rear view of a backlight module of FIG. 3A;

FIG. 3C is a local enlarged view of FIG. 3B;

FIG. 4 is a side view of a printed circuit board and a backlight module assembled in a flat panel display of an embodiment of the invention;

FIG. 5 is a side view of a printed circuit board and a backlight.module assembled in a flat panel display of another embodiment of the invention.

DETAILED DESCRIPTION

FIG. 3A is a schematic view of a front side F of a backlight module 20 of an embodiment of the invention.

FIG. 3B is a schematic view of rear side B of the backlight module 20 of FIG. 3A.

Note that the embodiment of the invention modifies connection between a flexible printed circuit board and an external circuit board in a flat panel display or a liquid crystal display, and thus, unrelated elements are eliminated from FIGS. 3A and 3B to clearly show the connection between flexible printed circuit board and the external circuit board.

As shown in FIGS. 3A and 3B, the backlight module 20 comprises a frame 21, a flexible printed circuit board 22, and at least one electrical connection port 26. The flexible printed circuit board 22 is connected to a light source (not shown), providing electric power thereto. The flexible printed circuit board 22 is encircled by the frame 21; that is, the flexible printed circuit board 22 does not protrude from the frame 21. Thus, the frame 21, requiring no notch for the flexible printed circuit board 22, provides increased strength. On the rear side B of the backlight module 20, the electrical connection port 26 is disposed on the flexible printed circuit board 22, connecting the flexible printed circuit board 22 and an external printed circuit board (not shown) or a printed circuit board of a flat panel display. Note that only two electrical connection ports 26 are shown in FIG. 3B, disposed on two ends of the flexible printed circuit board 22, respectively. The invention, however, does not limit the quantity, position, or size of the flexible printed circuit board 22.

FIG. 3C is a local enlarged view of FIG. 3B. As shown in FIG. 3C, the frame 21 comprises at least one opening 27 formed on the rear side B thereof, corresponding to the electrical connection port 26 passing through the opening 27 and exposed to the outside of the frame 21. The electrical connection port 26 comprises an elastic conductor such as a metal elastic plate, a curved metal plate.

FIG. 4 is a side view of a printed circuit board 25 and a backlight module 20 assembled in a flat panel display 200 of an embodiment of the invention. Note that other elements of the flat panel display 200 such as upper, lower covers, and panel are not shown to clearly show the connection. The panel can be a liquid crystal panel. In this embodiment, the flat panel display 200 further comprises a printed circuit board (PCB) 25 and a first electrical connection port 251, comprising bare copper. When the backlight module 20 is disposed on the PCB 25, since the electrical connection port 26 (second electrical connection port) of the backlight module 20 is a metal elastic plate, passing through the opening 27 and exposed to the outside of the frame 21 and protruding to the PCB 25, the electrical connection port 26 of the backlight module 20 contacts the bare copper 251 of the PCB 25 to electrically connect the flexible printed circuit board 22 and the PCB 25.

Additional space for the connector or welding portion is not required in the invention, and manual assembly of the connector and welding time are saved such that manufacturing time is reduced. Additionally, material costs of metal elastic plates are much less than those of connectors or solders with better quality control. Since the flexible printed circuit board and the PCB are not connected by welding, the device can be easily reassembled without any difficulties. The flexible printed circuit board is encircled by the frame with no portion protruding therefrom such that the frame has higher strength, reducing material costs.

FIG. 5 is a side view of a printed circuit board 35 and a backlight module 30 assembled in a flat panel display 300 of another embodiment of the invention, in which elements other than the printed circuit board 35 and the backlight module 30 are omitted.

In this embodiment, the backlight module 30 comprises a frame, a panel, a flexible printed circuit board, and at least one second electrical connection port 33, disposed on a surface of the flexible printed circuit board. The flat panel display 300 further comprises a first electrical connection port 36, disposed on a surface of a printed circuit board (PCB) 35. The backlight module 30 is connected to the printed circuit board 25. The difference is that the first electrical connection port 36 of the PCB 35 comprises an elastic conductor such as a metal elastic plate or a curved elastic plate, protruding to the backlight module 30. The second electrical connection port 33 comprises bare copper. The first electrical connection port 36 contacts the second electrical connection port 33 , connecting the flexible printed circuit board (not shown) in the backlight module 30 and the printed circuit board 35 of the flat panel display 300.

Hence, in the modified connection structure of the invention, direct contact between two electrical connection ports 36 and 33 conserves the space on the circuit board, providing easy reassembly, low costs, and high quality control, while increasing strength of the frame of the backlight module.

While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 

1. A backlight module, comprising: a frame; a circuit board, encircled by the frame; and at least one electrical connection port, disposed on, the circuit board, connecting the circuit board and an external circuit board.
 2. The backlight module as claimed in claim 1, wherein the frame comprises at least one opening, corresponding to the electrical connection port passing through the opening and exposed to the outside of the frame.
 3. The backlight module as claimed in claim 1, wherein the electrical connection port comprises an elastic conductor.
 4. The backlight module as claimed in claim 3, wherein the elastic conductor comprises a metal elastic plate.
 5. The backlight module as claimed in claim 1, wherein the electrical connection port is curved.
 6. The backlight module as claimed in claim 1, wherein the electrical connection port comprises bare copper.
 7. The backlight module as claimed in claim 1, wherein the circuit board comprises a flexible printed circuit board or printed circuit board.
 8. A flat panel display, comprising: a first circuit board; a first electrical connection port, disposed on a surface of the first circuit board; a backlight module, connected to the first circuit board, comprising: a frame; a second circuit board, encircled by the frame; and a second electrical connection port, disposed on a surface of the second circuit board; wherein the first electrical connection port contacts the second electrical connection port, connecting the second circuit board and the first circuit board; and a panel, connected to the second circuit board.
 9. The flat panel display as claimed in claim 8, wherein the first circuit board comprises a flexible printed circuit board or printed circuit board.
 10. The flat panel display as claimed in claim 8, wherein the second circuit board comprises a flexible printed circuit board or printed circuit board.
 11. The flat panel display as claimed in claim 8, wherein the frame further comprises an opening, corresponding to the second electrical connection port, passing through the opening, exposed to the outside of the frame, and protruding toward the first circuit board.
 12. The flat panel display as claimed in claim 8, wherein the second electrical connection port is curved.
 13. The flat panel display as claimed in claim 8, wherein the first electrical connection port comprises bare copper, and the second electrical connection port comprises an elastic conductor, protruding toward the first circuit board.
 14. The flat panel display as claimed in claim 13, wherein the elastic conductor comprises a metal elastic plate.
 15. The flat panel display as claimed in claim 10, wherein the first electrical connection port comprises an elastic conductor, protruding toward the backlight module, and the second electrical connection port comprises bare copper.
 16. The flat panel display as claimed in claim 15, wherein the elastic conductor comprises metal elastic plate.
 17. The flat panel display as claimed in claim 10, wherein the first electrical connection port is curved, protruding to the backlight module, and the second electrical connection port comprises bare copper.
 18. The flat panel display as claimed in claim 10, wherein the panel comprises a liquid crystal panel. 